The Effect of Jump on Evaluating Natural Resource Investments

The evaluation of mining and other natural resource projects is made particularly difficult by the high degree of uncertainty attaching to output prices. It is shown that the techniques of continuous time arbitrage and stochastic control theory may be used not only to value such projects but also to determine the optimal policies for developing managing. This paper describes a model for evaluating natural resource investments under uncertainty from a new perspective. The previous works in this field mostly regard the movements of natural resource prices as a continuous GBM process, which pays few attentions to the shock of unexpected bad news. Our model provides the first theoretical method to analyze the impact of such "jump" on investment decisions. It concludes that the more frequently bad news happens, the earlier a project will be invested.     

分形论与自然灾害研究—地震,洪涝灾害中的分形研究

在多种概念和方法相互撞击和汇合中诞生的分形论，提示了现实世界中具有深刻理论意义和广泛现实基础的幂指数律，给自然灾害研究提供了新的方法和途径。本文在初步介绍分形论有关基本概念的基础上，回顾了分形论在地震、洪涝灾害中的一些应用和新近进展，展示了分形论在自然灾害研究中的前景。     

湖南省主要自然灾害及减灾策略

本文概述了湖南省的干旱、洪涝、低温冷害、冰雹、风灾、冰冻、农业病虫害、森林火灾水土流失、地震等主要自然灾害的时空分布特征及其对国民经济的影响,并对主要灾害的发展作出了预测,最后提出了减灾策略。     

There will be blood: Crime rates in shale-rich U.S. counties

Over the past decade the production of tight oil and shale gas significantly increased in the United States. This paper examines how this energy boom has affected regional crime rates throughout the country. We find positive effects on rates of various property and violent crimes in shale-rich counties. In 2013, the cost of the additional crimes in the average treatment county was roughly $2 million. These results are not easily explained by shifts in observed demographics like gender and age. There is however evidence that people with criminal records (registered sex offenders) moved disproportionally to shale-boom towns in North Dakota. We also document a rise in income inequality (a postulated determinant of criminal activity) that coincides with the timing of the energy boom. Policy makers in boom towns should anticipate these crime effects and invest in public infrastructure accordingly.     

Empowering Indigenous natural hazards management in northern Australia

Northern Australia is prone to recurring severe natural hazards, especially frequent cyclones, flooding, and extensive wildfires. The region is sparsely populated (≪ 0.5 persons km⁻²), with Indigenous (Aboriginal) residents comprising 14% of the population, and typically the majority in remote regions. Despite national policy committed to addressing emergency management (EM) in vulnerable Indigenous communities, implementation remains unfunded. We synthesise participatory intercultural research conducted over seven years exploring core challenges, opportunities and potential solutions towards developing effective EM partnerships. Similar EM engagement and empowerment issues face First Nations and local communities in many international settings. In search of solutions, we explore developing effective partnership arrangements between EM agencies and culturally diverse Indigenous communities. Observing that government already provides substantial investment in cultural and natural resource management programmes conducted by over 150 Indigenous Ranger Groups (IRGs) nationally, we demonstrate that expansion of IRG roles to incorporate EM community engagement and service delivery can provide multiple cost-effective community and business development benefits for many remote communities.     

Carbon and hydrogen isotope effects during sorption of organic contaminants on carbonaceous materials

Stable carbon and hydrogen isotopes can be an efficient means to validate biodegradation of organic contaminants in groundwater since it results in an isotopic fractionation. A prerequisite in applying this method in the field is the proof that other processes decreasing the contaminant concentration are conservative with respect to isotope effects. In this paper we show for carbon isotopes of halogenated hydrocarbon compounds [trichloroethene (TCE), cis-dichloroethene (c-DCE), vinylchloride (VC)] and carbon and hydrogen isotopes of BTEX compounds (benzene, toluene, p-xylene) that no significant fractionation occurs during equilibrium sorption onto activated carbon, lignite coke and lignite. In general, effects were in the range of the reproducibility limit of the analytical instrument (0.5 per thousand for delta13C, and 8 per thousand for delta2H). This observation was made for fractions sorbed of less than 5% to more than 95%. Also for rate-limited sorption of TCE onto activated carbon, no significant fractionation in carbon isotopes could be observed. These findings support the assumption that for these classes of compounds, sorption processes in aquifer systems are conservative with respect to isotope effects.     

微藻处理城市污水反渗透浓水的条件优化

城市污水回用是缓解水资源危机的有效措施。反渗透工艺是生产优质再生水的重要方法,但在实际应用过程中,25%~50%的城市污水会转化成反渗透浓水 (ROC) 。ROC的总氮 (TN) 、总磷 (TP) 和硬度离子 (Ca²⁺、Mg²⁺) 质量浓度等指标较高。利用微藻去除氮、磷和Ca²⁺、Mg²⁺是城市污水ROC处理的有效途径之一,且可实现资源回收,但目前对其应用条件的优化研究仍较少。利用微藻Scenedesmus sp. FACHB-1574处理城市污水ROC,在不同总溶解性固体 (TDS) 质量浓度 (1.35 g·L⁻¹和2.70 g·L⁻¹) 、光暗时间比 (12 h/12 h、16 h/8 h、20 h/4 h、24 h/0 h) 、光强 (25 μmol·m⁻²·s⁻¹、50 μmol·m⁻²·s⁻¹、100 μmol·m⁻²·s⁻¹) 和氮磷质量比 (107:1、14:1、7:1) 的条件下,研究了微藻对污水的处理效果及其生长状况。结果表明,Scenedesmus sp. FACHB-1574可适应城市污水ROC中TDS质量浓度为2.70 g·L⁻¹的条件;对TN的去除速率随光照时间和光强的增加而增大;氮磷质量比为14:1时微藻对TN的去除速率及微藻生物量等性能均得以强化。在最优处理条件下 (光暗时间比20 h/4 h,光强100 μmol·m⁻²·s⁻¹,氮磷质量比14:1) 处理10 d后,微藻对城市污水ROC中TN和TP去除率分别为92.83%和99.68%,藻密度、质量浓度 (干重) 、脂质含量分别为23.62×10⁶ cells·mL⁻¹ 、1.10 g·L⁻¹、34.55%。随着微藻的生长,在无CO₂的条件下,废水的pH值从7.5升高到10.7,并可去除52.7%的Ca²⁺和33.9%的Mg²⁺。本研究可为微藻在城市污水处理及资源化工艺中的应用提供参考。     

Sustainability of wild plant use in the Andean Community of South America

Overexploitation is the second biggest driver of global plant extinction. Meanwhile, useful plant species are vital to livelihoods across the world, with global conservation efforts increasingly applying the concept of ‘conservation-through-use.’ However, successfully balancing conservation and biodiversity use remains challenging. We reviewed literature on the sustainability of wild-collected plant use across the countries of Colombia, Ecuador, Peru, and Bolivia—a region of global importance for its biological and cultural richness. After applying defined search terms and a two-stage screening process, 68 articles were reviewed. The numbers which reported sustainable, unsustainable, or context-dependent outcomes were relatively even, but national differences emerged. Through narrative synthesis, we identified five key, reoccurring themes: plant biology; land tenure; knowledge, resource, and capacity; economics and market pressures; and institutional structures, policy, and legislation. Our results show the need for flexible, context-specific approaches and the importance of collaboration, with bottom-up management and conservation methods involving local communities and traditional ecological knowledge often proving most effective. Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01529-7.     

神农架国家级自然保护区樟科资源植物分析

神农架樟科植物种类共有 7属 3 1种 (含变种 ) ,资源植物十分丰富 ,按其用途可分为观赏植物类、蜜源植物类、药用植物类、木材植物类、香料植物类、工业用油脂植物类及珍稀保护植物类等。这些资源植物具有较大的开发利用价值。     

Early Development of Systems Analysis in Natural Resources Management from Man and Nature to the Miami Conservancy District

Contemporary approaches to natural resources and environmental decision-making typically draw on a “systems” perspective to assess and improve management strategies. This paper describes the early genesis of the systems analysis approach. It concentrates on a period between the mid-19th to early 20th centuries. During the early part of this period, George Marsh's Man and Nature and related works laid out an approach to problem-solving that recognized the relationship among physically disperse elements in the environment, the need to balance benefits against costs, the potential for using quantitative modeling to understand management options, and the importance of integrating human and natural components into solutions. In the early 20th century, the Miami Conservancy District project brought this approach to fruition with its use of complex simulation and optimization modeling, detailed cost–benefit analysis, and its linking of economics, engineering, science, and law into a far-reaching solution to a complex water resources problem. The objective of this paper is to describe the early development and application of this conceptual approach to problem-solving. An examination of the origins of natural resources systems analysis can broaden one's perspective of the contemporary field to understand its roots as a philosophy for environmental problem-solving.